Update milestone and label workflows for maintainers, developers, and bots (#3342)

* Initial plan

* Update milestone workflow: rename and add BornToBeRoot maintainer

Co-authored-by: BornToBeRoot <16019165+BornToBeRoot@users.noreply.github.com>

* Add label workflow and remove duplicate labels from dependabot config

Co-authored-by: BornToBeRoot <16019165+BornToBeRoot@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: BornToBeRoot <16019165+BornToBeRoot@users.noreply.github.com>

Author: Copilot

.github/dependabot.yml

@@ -7,8 +7,6 @@ updates:
   target-branch: main
   commit-message:
     prefix: "Dependency (dependabot/nuget):"
-  labels:
-  - ":heavy_check_mark: dependencies"
 - package-ecosystem: "dotnet-sdk"
   directory: "/Source"
   ignore:
@@ -20,14 +18,10 @@ updates:
   target-branch: main
   commit-message:
     prefix: "Dependency (dependabot/dotnet-sdk):"
-  labels:
-  - ":heavy_check_mark: dependencies"
 - package-ecosystem: "npm"
   directory: "/Website"
   schedule:
     interval: weekly
   target-branch: main
   commit-message:
     prefix: "Dependency (dependabot/npm):"
-  labels:
-  - ":heavy_check_mark: dependencies"

.github/workflows/label.yml

@@ -0,0 +1,25 @@
+name: Assign label to PRs
+
+on:
+  pull_request_target:
+    types: [opened, reopened]
+
+jobs:
+  assign-dependencies-label:
+    name: Assign dependencies label
+    runs-on: ubuntu-latest
+    if: contains(fromJSON('["dependabot[bot]", "transifex-integration[bot]", "imgbot[bot]"]'), github.event.pull_request.user.login)
+    permissions:
+      issues: write
+      pull-requests: write
+    steps:
+      - name: Assign label
+        uses: actions/github-script@v7
+        with:
+          script: |
+            await github.rest.issues.addLabels({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.payload.pull_request.number,
+              labels: [':heavy_check_mark: dependencies']
+            });

.github/workflows/milestone.yml

@@ -1,4 +1,4 @@
-name: Assign milestone to automated PRs
+name: Assign milestone to PRs
 
 on:
   pull_request_target:
@@ -8,7 +8,7 @@ jobs:
   assign-milestone:
     name: Assign next-release milestone
     runs-on: ubuntu-latest
-    if: contains(fromJSON('["dependabot[bot]", "transifex-integration[bot]", "imgbot[bot]", "Copilot"]'), github.event.pull_request.user.login)
+    if: contains(fromJSON('["dependabot[bot]", "transifex-integration[bot]", "imgbot[bot]", "Copilot", "BornToBeRoot"]'), github.event.pull_request.user.login)
     permissions:
       issues: write
       pull-requests: write